import java.util.Scanner;

public class Job04 {
    public static void main(String[] args) {
        Scanner input = new Scanner(System.in);
        int sum =0;
        int count=0;
        do{
            int age = input.nextInt();
            ++count;
            sum += age;

        }while(count<=5);
        System.out.println("平均年龄是："+sum/count);
    }
}
